Have you done C/C plates. After the install of my c/c's on my '03, my car will "pop" when stopping on a hill, or sometimes just braking hard when the front end dives a bit. Apparently on mine (Steeda c/c's) there is a metal bearing inside that is responsible for my "pop" Whats supposed to hold it in place has apparently broken, and steeda wants the old ones before they will give me a new set. I was told it wont hurt anything but my sanity so Ive just delt with it.